Don't feel like looking it up, but we have reasonable attendance compared to others that aren't behemoths. The problem, to me, isn't the size of the stadium, it's that a huge share of the crowd is, and always will be, visiting fans from said behemoths. There are just too many other school alums/fans in Chicago, we are arguably the best destination in the B1G, we are centrally located in the conference with a huge airport nearby. Now, we could make the stadium a lot smaller like some have said, but I don't imagine we want to give up, say, $5M a year in visiting fan revenue.
Edit: even if we shrink the stadium, the OSU fans of the world will just start paying our ST holders like 500 bucks a ticket, and we will just have a smaller crowd still dominated by unfriendlies.